The invention is based on a handheld for contactless distance measurement.
Handheld devices of this kind measure the distance of a pertinent object from a reference point, against which a corresponding measuring stop of the handheld device is placed. Such a handheld device can be designed as a laser measuring device, an ultrasound measuring device, or a high-frequency measuring device. In any case, the distance is determined by measuring the travel time of a pulse emitted by the handheld device, reflected against the pertinent object, and received again by the handheld device.
In a known handheld distance measuring device (DE 196 52 438 C2), a linear measuring stop is constituted by the longitudinal edge of the back side of the housing, which tapers to a point, wherein the transition region from the housing top and the housing bottom to the longitudinal edge is rectilinear or curved in an arc shape. The middle part of this longitudinal edge, including the associated transition region to the housing top and housing bottom, is embodied so that it can turn around a rotation axis parallel to the measuring direction so that it can be turned by an arbitrary rotation angle in relation to the two outer, stationary parts of the longitudinal edge. If the middle and the two outer parts of the longitudinal edge are flush with one another, then this longitudinal edge of the back of the distance measuring device can be brought to rest, for example, against a corner line formed by two walls, thus allowing the diagonals of a room to be measured. Since the longitudinal edge lies in the reference plane for the distance measurement, then the value indicated on the display of the distance measuring device is the actual distance from the corner line to the pertinent object, for example the diagonally opposite corner of the room. On the other hand, if the distance measuring device is used for measurements starting from surfaces oriented toward the object, e.g. walls, ceilings, floors, then the middle region of the longitudinal edge, including the associated transition region, must be turned by an arbitrary rotation angle, e.g. by approx. 90°. Since the rotation axis is aligned parallel to the measuring direction, the parts of the longitudinal edge that are rotated in relation to one another by the rotation angle always lie in a plane perpendicular to the measuring direction. Consequently, the measuring direction is steadily aligned at right angles to a planar guide surface and the distance is measured from the stop surface to the pertinent object. The result displayed by the distance measuring device corresponds exactly to the distance from the selected stop surface to the pertinent object, without requiring a conversion or an adjustment in the distance measuring device.
In a likewise known distance measuring device (DE 198 04 051 A1), the linear measuring stop for placement against a reference line, e.g. the corner line between two walls, is eliminated and a flat measuring stop is embodied on the planar back wall of the housing. In the event that a measurement is to be made starting from an outside edge, i.e. the guide edge for the distance measuring device is oriented away from the object to be measured, an additional stop is provided, which is embodied on the inside of a pivoting flap pivotably connected to the housing. When the additional measuring stop is not in use, the pivoting flap is folded against the bottom of the housing and, in order to activate the additional measuring stop, can be pivoted out from the housing by 90°. In this pivoted position of the pivoting flap, the additional measuring stop is oriented toward the object to be measured and lies in the reference plane for the distance measurement so that after the additional measuring stop is placed against the outer edge and the measuring operation is triggered, the distance value indicated on the display is the actual distance of the pertinent object from the guide edge.